Metal Hardness Meter High Accuracy Digital Portable Hardness Gauge for Steel Copper Brass Cast Iron Aluminum Testing US Plug Item Type: Metal Hardness Tester Hardness Standard: HL, HB, HRB, HRC, HRA, HV, HS Display Error: ±6%(HLD=800) Display Repeatability: 0.8%(HLD=800) Display: Industrial Grade 128x64 Graphic Dot Array LCD Power Supply: 1 x 1800mAh Rechargeable Battery (built in) Continuous Working Time: About 20 Hours Working Temperature: -10-50℃ Storage Temperature: -30-60℃ Relative Humidity: ≤90% Material Hardness Impact Device D DL Steel and Cast Steel HRC 17.9-68.5 20.6-68.2 HRB 59.6-99.6 37.0-99.9 HRA 59.1-85.8 HB 127-651 81-646 HV 83-976 80-950 HS 32.2-99.5 30.6-96.8 Forged Steel HB 143-650 Alloy Tool Steel HRC 20.4-67.1 HV 80-898 Stainless Steel HRB 46.5-101.7 HB 85-655 HV 85-802 Grey Cast Iron HRC HB 93-334 HV Nodular Cast Iron HRC HB 131-387 HV Cast Aluminum Alloy HB 19-164 HRB 23.8-84.6 Brass HB 40-173 HRB 13.5-95.3 Bronze HB 60-290 Copper HB 45-315